1. Our place in the Universe

2. This is what we think our galaxy, the Milky Way, looks like.
The Sun is about ½
way from the center
on a galactic arm
The Sun
takes 225 million
years to orbit the
center
The sun is NOT this big NOR is
it a star shape (shhh it’s round).

3. The Sun is NOT the biggest star!
109 Earths fit across the diameter of the SUN.
You can fit 1.3 million Earths INSIDE the Sun
The Sun, the planets and anything that orbits the Sun is called the Solar System.

4. These stars are bigger
These stars are
NOT the biggest
either
The SUN

5. These are!!!
The sun is so small in this picture that it takes as much space as ONE pixel of this image!!!!

6. Average?
We estimate that there are between 100 and 400 billion stars in the Milky Way Galaxy.
The Sun is an average star in size and temperature.
Every star you see at night are stars that are MUCH bigger and MUCH brighter than the Sun.

7. Is the Milky Way the only galaxy out there???
NO WAY!!!
We are one of billions!
* We estimate there are over 100 billion GALAXIES beyond our own!

8. Hubble Ultra Deep Field (HUDF)
Hubble took 11 days to look at a spot in the sky that appeared to be empty. This is what it found.
Every point of light you see is another galaxy filled with 100s of billions of stars.

9. Where did they all come from?
BANG!!! (the big one)

10. What is the BB?
Approximately billion years ago (bya) or, 13,820,000,000 yrs. there was an explosion OF space and time (not IN space and time like normal sized bangs).
So, in short, the Big B was the formation of our Universe (all energy, matter, and space-time)
BANG!!!

11. E= mc2 Energy = matter x speed of light squared
It means energy can be converted to matter and vice-versa.

12. Does it matter? Initially after the Big Bang there was only Energy.
As the universe expanded, it cooled. This allowed the first subatomic particles to form (protons, neutron, electrons).
The simplest elements were the first to form. Hydrogen and helium. The fuel for STARS!

13. Is there any evidence of the BB?
YUP!!! There are TWO main pieces of evidence:
1. The universe is expanding…
2. In every single direction we look in space we see…
Cosmic Background Radiation
That’s left over energy from the Big Bang bouncing around the universe.

14. Here is a map of it
You have to imagine that this is our entire 3-dimensional view of the sky flattened into a map.
EVERY 3-dimensional direction we look we see CBR (cosmic background radiation).